Sponge



FIG. 1 is a perspective view of the sponge;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The height of the claimed design in shown broken away in the views to indicate indeterminate size. The broken lines depicting the bottom area of the sponge are for illustrative purposes only and form no part of the claimed design. 

CLAIM The ornamental design for a sponge, as shown, and described. 